[!INFO] From radiopaedia
Effect of duration of lithium accumulation
Side effects occuring at therapeutic range:
Drugs interfering with renal excretion of lithium: Thiazides >> loop diuretics, ACEi, ARB, NSAIDS,
The syndrome of irreversible lithium-effectuated neurotoxicity (SILENT): prolonged neurologic and neuropsychiatric features which may not resolve despite stopping lithium.
Lithium is teratogenic -> Ebsteins anomaly.
[[DNAFolateB12Deficiency.png]]
Source
[!INFO] Key points:
- The synthesis of methionine from homocysteine is catalyzed by methionine synthase, an enzyme that requires not only folate (as 5-methyltetrahydrofolate) but also vitamin B12.
- 3 vitamins are interlinked : B12, B9 and B6
- Thus, the concentration of homocysteine in the blood is regulated by three B-vitamins: folate, vitamin B12, and vitamin B6
| Folate | B12 |
| :--------------------------------------------------------------------------------------------------------------: | :-------------------------------------------------------------------------------------------------------------------------: |
| green leaves (mnemonic: folate = foliage) | Animal sources |
| 4 months of stores | 2 years of stores |
| large percentage destroyed in cooking | Only little destroyed in cooking |
| Absorption is mainly in the duodenum and jejunum Source | Terminal ileum by receptor mediated endocytosis. Source |
Presentation
Labs:
Management
Urea is elevated in acute dehydration.
Mechanism: Source
[!INFO] Shortcuts
- For PAH : clearance = renal blood flow.
- For inulin: Clearance = GFR
Side effects of Erythropoietin treatment:
There are a number of reasons why patients may fail to respond to erythropoietin therapy:
[!INFO] Mnemonic:
Poor penetration : BAT CAVE (deep dark corners = poor penetrance)
- Beta lactams
- Aminoglycosides
- Tetracyclines
- Clindamycin
- Amphotericin
- antiretroViral (tenofovir)
- Echinocandins and other antifungals
Cephalosporins:
| Toxin | Antidote | |
|---|---|---|
| Acetaminophen | N-Acetylcysteine | |
| Anticholinergics | Physostigmine* | |
| Anticoagulants, oral factor Xa inhibitors (apixaban, edoxaban, rivaroxaban) | Andexanet alfa | |
| Benzodiazepines | Flumazenil* | |
| Black widow spider bite | Lactrodectus antivenom | |
| Botulism | Botulinum antitoxin | |
| Beta-blockers | Glucagon, IV lipid emulsion | |
| Calcium channel blockers | Calcium IV insulin in high doses with IV glucose IV lipid emulsion |
|
| Carbamates | Atropine Pralidoxime chloride | |
| Crotaline snake bites (US) | Crotalinae polyvalent immune Fab (ovine) | |
| Cyanide | Hydroxocobalamin Cyanide antidote kit (includes amyl nitrate, sodium nitrite, and sodium thiosulfate) | Vit B12 forms cyanocobalamin which restores mitochondrial function |
| Dabigatran | Idarucizumab | |
| Digitalis glycosides (eg, digoxin, digitoxin, oleander, foxglove) | Digoxin-specific Fab fragments | Fab = Antigen binding fragments |
| Ethylene glycol | Fomepizole Ethanol | [[2021 General Medicine July#Methanol poisoning]] (alcohol dehydrogenase inhibitor) |
| Heavy metals | Chelating drugs (see table Guidelines for Chelation Therapy) | heavy metals: Dimercaprol (aka British anti-lewisite) Cobalt, Pb, Zn : Edetate calcium sodium Au,Pb,AS : Penicillamine Succimer |
| Ionizing radiation | Potassium iodide | |
| Iron | Deferoxamine | |
| [[Tuberculosis#Isoniazid|Isoniazid]] | Pyridoxine (vitamin B6) | Pyridoxine (B6) |
| Methanol | Fomepizole Ethanol | Prevents formation of glycolic acid and glycloxylic acid by alcohol dehydrogenase. |
| Methemoglobin-forming agents (eg, aniline dyes, some local anesthetics, nitrates, nitrites, phenacetin, sulfonamides, dapsone). | Methylene blue Exchange transfusion Hyperbaric oxygen |
Hb has Fe3+ instead of 2+. (poor O2 capacity). Blue Skin. Dark blood. |
| Methotrexate | Leucovorin (folinic acid) Glucarpidase (carboxypeptidase-G2) | |
| Opioids | Naloxone | |
| Organophosphates | Atropine, Pralidoxime | See above |
| Scorpion envenomation (Centruroides sp) | Centruroides immune F(ab’)2 | |
| Sulfonylurea | Octreotide | Somatostatin analog; prevents calcium entry into beta cells -> inhibits insulin release. Prevents rebound hypoglycemia in sulfonylurea overdose. |
| Thallium | Prussian blue | |
| Tricyclic antidepressants | Sodium bicarbonate | |
| Unfractionated heparin | Protamine | |
| Valproic acid | L-Carnitine†| |
| Warfarin | Vitamin K Fresh frozen plasma Prothrombin complex concentrate (PCC) |
#2021BSQ-NOV/Q54
Aporecaeruloplasmin + 6 Cu atoms = ceruloplasmin (the major circulating form of Copper)
Mutations in ATP7B in Wilson disease impairs both the incorporation of copper into apoceruloplasmin and the excretion of copper into bile.
- Impaired incorporation of copper into ceruloplasmin leads to misfolding of the protein and shorter plasma half life. This reduces serum caeruloplasmin level.
- Serum copper levels are usually lower than normal.
- Because of deficiency of ceruloplasmin in the serum.
- Accumulation of non ceruloplasmin bound free copper causes copper deposition in other organs.
- Release of large amounts of copper into the blood due to hepatic necrosis can cause haemolysis.
- Haemolysis + liver disease => think of Wilson's.
Diagnosis
[!TIP] Eyes and basal ganglia and of course liver
Source
Foscarnet and cidofovir are toxic.
See [[Anaemia#Folate and B12 metabolism]]